Springfield Police Department photoDennis Ramos Diaz, left and Armando Olivares were charged Tuesday with the November murder of Reality Shabazz Walker.

UPDATE, 1:30 p.m.: Police have confirmed two additional suspects in the case:

Lionel Lopez, 18, of 86 Calhoun St. will be served with a warrant, Sgt. John M. Delaney said. Lopez is already being held awaiting trial for the Dec. 7 murder of 17-year-old Jose Colon.

Javier Nieves, 18, 115 Forest Hill St. Boston was arrested earlier today. Hampden District Attorney Mark G. Mastroianni said Nieves came to Springfield District Court this morning after hearing there was a warrant for his arrest. He was taken to Springfield police headquarters for booking and will be arraigned along with Dennis Diaz and Armando Olivares this afternoon.

Both men were arrested without incident at their respective addresses. Diaz was taken into custody by detectives assigned to the homicide unit, Delaney said, while Olivares was arrested by warrant apprehension unit detectives Bobby Bohl and John Leonard along with members of the U.S. Marshals Fugitive Task Force.

Walker, a 2010 graduate of Springfield Academy High School, was gunned down just after midnight on Nov. 30 outside of the John L. Sullivan housing complex off Stafford St. in Springfield. At the time of his death, he was enrolled in the medical assisting program at the American Career Institute in Springfield.